The Acer XB280HK monitor can not connect to the new Thunderbolt 3 port on the 2018 MacBook Pro

My Acer XB280HK monitor works fine with my old MacBook Pro and Thunderbolt 2 port, but neither the HDMI to Thunderbolt 3 cable nor the Thunderbolt 2 to 3 adapter get the monitor. Can anyone recommend a cable or adapter that works?